Available information that is relevant to operation of a business or of a household increases at an exponential growth rate. A user of such information must become concerned with how to find the time, in an already crowded workday, to absorb the most relevant of such information. A menu of such information can be provided on a subscription basis, for individual selection by each user, as discussed in U.S. Ser. No. 08/643,963. One useful medium for delivery and reception of such information is sound, which requires use of the ears and of a portion of the user's brain but does not require simultaneous use of other senses. Previous systems have usually provided this information as a combination of video and audio in which the audio information was often treated as an afterthought.
The approaches disclosed by previous workers in this field usually combine video and audio data so that the video requirements control the choice of transmission system, or the selection of audio information is limited to features closely associated with use of a telephone. These approaches do not provide transmission and storage of a wide variety of audio-only information in a format that takes advantage of unique features of audio format information.
Also, these approaches do not take advantage of the possibility of using an available transmission medium, such as an internet that already provides for inter-communication between millions of homes, offices and other facilities. Use of a particular internet may reduce the number of signal formats that must be recognized and dealt with, and it may be possible to optimize the audio signal processing for the limited number of (or one) formats in which the audio signals are received.
What is needed is a procedure for packaging, delivery, reception, storage and playback of audio files in a format that (1) allows for potential transmission of the audio files at transfer rates many times higher than the normal audio playback rates, (2) allows receipt and storage of the audio files in compressed formats that can store several hours of normal audio programming in a playback medium of modest size, (3) allows transmission of audio files to the user at times and manners that are convenient for both the sender and the recipient, and (4) allows the user to conveniently transport the stored audio files, for playback at a time chosen by the user.
Preferably, the procedure should be adjustable to receive and process the audio (or text data) files using a signal processing procedure that is optimizable or optimized for the format, or limited number of formats, in which the audio (or text data) files are delivered to audio playback apparatus.